For an oxide thin film transistor (TFT) of the back-channel-etching (BCE) type in the related art, a source electrode and a drain electrode are arranged directly on an active layer, i.e., there is no etch stopping layer (ESL) being arranged between the source/drain electrode and the active layer. Due to lack of a protection by the ESL, a portion of the active layer which is not covered by the source/drain electrode may be adversely affected by subsequent manufacture process, environment where the active layer is located after being manufactured, or the like, thereby to influence performance of an oxide thin film transistor.